Poor Kelly Rutherford. The ‘Gossip Girl’ star lost her two small children to ex-husband Daniel Giersch. Now a top family law attorney explains what may have gone wrong with her case.

Is that the reason that the judge ruled that her children, son Hermes, 5, and daughter Helena, 3, would have to live in France with her ex, instead of continuing to be raised here in NYC, with her as they always had?

That’s a strong possibility believes top Manhattan family law attorney, Malcolm Taub, a partner in Davidoff, Hutcher & Citron LLP.

“Family court judges don’t want one parent to try and alienate kids from the other parent. One of the characteristics of being a good parent is promoting a relationship with the other parent,” explains Taub.

In the judges decision, the judge chose to make Kelly’s ex husband the “residential parent” because “Daniel facilitated the relationship of the children with Kelly… and Kelly simply has not done so,” reports TMZ.

The judge cited the example of Kelly repeatedly failing to put Giersch’s name on their daughter’s birth certificate, despite being asked several times by the court, TMZ writes.

The situation now puts Kelly in a tough position believes Taub. “Unless there is egregious evidence, a court will not overturn the order right now,” he says. However, he does think there is hope that Kelly may be able to regain custody of her little ones in the future.

“The fact that there’s a ruling doesn’t mean its written in stone. Her best option is to stop appearing in the media, keep a low profile, show contrition, demonstrate that she’s a loving, caring mom and stop knocking her ex on TV. The TV audience doesn’t have a vote,” he points out.

He also urges her to try and improve her relationship with her ex. “A lot of time when people calm now, they come to arrangements which work for them,” he advises.

He’s not encouraged by an option suggested to Kelly by top attorney and Harvard law professor Alan Dershowitz to appeal to a federal court, claiming that Kelly’s children’s constitutional rights have been violated since they’ve been forced to move to France.

“Even if Kelly won custody based on this ruling, she still would have to get a custody order in France,” he explains.

Taub re-emphasizes that, for Kelly, her best option to return her children to the U.S. is to “off the offensive and try to work out a situation with ex-husband Daniel that is reasonable.”